How much of energy is transferred from one trophic level to another?

The correct answer is Option (2) -10%

In ecological systems, only about 10% of the energy from one trophic level is transferred to the next trophic level. This is known as the "10% rule" or "energy pyramid" and it limits the number of trophic levels an ecosystem can support. The remaining 90% of energy is lost as heat through metabolic processes, movement, and other life activities. Thus, each subsequent trophic level receives only a fraction of the energy available at the previous level.